Protein Synthesis Initiation in Bacteria

Marianne Grunberg‐Manago, Institute of Physico‐chemical Biology, Paris, France
Sean M Studer, University of California, San Diego, CA, USA
Simpson Joseph, University of California, San Diego, CA, USA

Published online: December 2007

DOI: 10.1002/9780470015902.a0000542.pub2

Translation initiation begins with the assembly of the pre-initiation complex followed by the formation of the initiation complex. The process of initiation then continues until the first peptide bond is formed; it is at this point that translation begins. The formation of the pre-initiation/initiation complex is often the rate-limiting step during the process of translation, as it is influenced by a number of translational regulatory mechanisms. As a result, the process of initiation can play a significant role in gene expression.

Keywords: initiation factors; translation; Shine–Dalgarno sequence

Figure 1. The figure illustrates the bacterial pre-initiation complex unfolding a structured mRNA. A structured mRNA (shown in grey, the red region illustrates the SD sequence) first interacts with the pre-initiation complex through a ‘standby-site’. Following this interaction the pre-initation complex unfolds the mRNA through a passive process resulting in the SD sequence base pairing with the ASD (shown in cyan).
Figure 2. The final stages of translation termination followed by the subsequent steps involved in the formation of the translation initiation complex. Key: 50S subunit (50S), 30S subunit (30S), elongation factor GTP (EF-G), initiation factor 1 (1), initiation factor 2 (2), initiation factor 3 (3), messenger RNA is noted as the grey, curved line and the tRNA is noted as the vertical linear object that is spherical at the bottom.
Figure 3. Location of initiation factors on 30S ribosomal subunit. 1, 2 and 3 refer to initiation factors IF1, IF2 and IF3, respectively. The head, cleft, body and platform of the 30S subunit are marked to aid orientation.
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Related Sub-Topics:

Translation and Protein synthesis | Translation of RNA | Translational Regulation | Bacteria | Biosynthesis
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Article Title: Protein Synthesis Initiation in Bacteria
 
How to Cite close
Grunberg‐Manago, Marianne, Studer, Sean M, and Joseph, Simpson(Dec 2007) Protein Synthesis Initiation in Bacteria. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0000542.pub2]